With the holidays fast approaching, many of are remembering the days when we believed in Santa Claus. Even if you weren't raised in a household that celebrated Christmas, many kids still grow up with the idea that Santa is a real person who delivers presents on the evening of Dec. 24. But why do we believe in Santa Claus? Like many cultural touchstones, this one goes back into history and psychology; it's pretty fascinating to break down, so let's take a closer look.

Writing about her own exprience realizing that Santa wasn't real for Psychology Today, Vanessa LoBue, Ph.D. discusses why it's both normal and important for kids to believe in Santa and in fantasy. "Children spend a large amount of time pretending, especially between the ages of five and eight. They are also constantly exposed to media where animals can talk, people can fly, and objects magically appear out of thin air," she explains. "So why would a group of flying reindeer be any more fantastical than a talking mouse or singing snowman? Although magical thinking decreases between the ages of seven and nine (around the same age at which most children give up the myth of Santa Claus), it doesn't disappear forever."

LoBue makes an important point, here: While some people feel that believing in Santa is controversial or an unnecessary lie to tell children, it's interesting to think about how important imagination and fantasy are to a child's development — and how much of their non-Santa-related media is based on fantasy anyway.

So do generations of children keep believing in Santa because they're prone to fantasy at that age? Jacqueline D. Woolley at Live Science agrees with this notion, but pushes it a step further, suggesting that kids believe in the Santa fantasy at least in part because parents use their authority to make Santa appear as real as possible.

"Parents and others go to great lengths to support the Santa myth," Woolley explains. "In a recent study we found that 84 percent of parents reported taking their child to visit more than two Santa impersonators during the Christmas season." The idea here is that while kids are imaginative, they're not willing to believe just anything at face value. So when adults go through extra effort to "prove" Santa is real, kids make an evaluative judgment on whether he is, indeed, a real person.

So, when do kids really stop believing in Santa? According to a recent survey from the Associated Press, it looks like while more than 80 percent of people admit to believing in Santa as a child, the average age people stopped believing in Santa was about 8 years old.

Like LoBue explained, this is also around the age where kids are transitioning out of their "fantasy" stage and are gaining different abilities in evaluation and judgment. Basically, they're of an age where they're starting to question their parents further and look for more answers.

So why do kids believe in Santa? While as adults we all know Santa is not real, it's pretty easy to understand how kids think he certainly could be. Psychology and development puts them right in that imaginative sweet spot, and let's be real: Kids also trust their parents and other authority figures, like teachers, to guide them to the truth. So when all the adults in the room are talking about Santa,of course kids are going to buy into it... at least for a few years.